Correlation of Electromagnetic Interference in Inverter and Radio Disturbance on Assessment of Component and Battery Electric Vehicle

Electromagnetic interference generated by the power modules of the inverter in battery electric vehicles causes degradation of the radio broadcasting performance in vehicle antennas. The discrepancies in the input impedance from the inverter between the assessment of the component and vehicle could affect the common mode current. In this study, the correlation between the conducted currents in both the components and the battery electric vehicle was evaluated. In addition, the relationships between the electromagnetic interference in the inverter, the drive shafts, and the interference voltage at the radio antenna cable are also examined. The correlations were investigated experimentally and computationally using the common mode ferrite core and Y capacitance for frequencies ranging from 150 kHz to 30 MHz. The result showed that the common mode current in the vehicle is significant high at 1.2 MHz with only Y capacitance installed in the vehicle (no ferrite core), which was attributable to a lower input impedance from the inverter in the vehicle. In addition, our study demonstrated the strong correlations between the common mode current, the electric field at the drive shaft, and the voltage at the radio antenna. The investigation results provide suggestions for appropriate suppression for the electromagnetic interference at the early design stage of the component, taking into account the gap of the impedance characteristic in the vehicle.